diff options
| -rw-r--r-- | kernel/trace/Kconfig | 14 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 23 |
2 files changed, 37 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 420ff4bc67fd..f468767bc287 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -915,6 +915,20 @@ config EVENT_TRACE_TEST_SYSCALLS TBD - enable a way to actually call the syscalls as we test their events +config FTRACE_SORT_STARTUP_TEST + bool "Verify compile time sorting of ftrace functions" + depends on DYNAMIC_FTRACE + depends on BUILDTIME_TABLE_SORT + help + Sorting of the mcount_loc sections that is used to find the + where the ftrace knows where to patch functions for tracing + and other callbacks is done at compile time. But if the sort + is not done correctly, it will cause non-deterministic failures. + When this is set, the sorted sections will be verified that they + are in deed sorted and will warn if they are not. + + If unsure, say N + config RING_BUFFER_STARTUP_TEST bool "Ring buffer startup self test" depends on RING_BUFFER diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 9ca63df6553a..403e485bf091 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6388,6 +6388,27 @@ static int ftrace_cmp_ips(const void *a, const void *b) return 0; } +#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST +static void test_is_sorted(unsigned long *start, unsigned long count) +{ + int i; + + for (i = 1; i < count; i++) { + if (WARN(start[i - 1] > start[i], + "[%d] %pS at %lx is not sorted with %pS at %lx\n", i, + (void *)start[i - 1], start[i - 1], + (void *)start[i], start[i])) + break; + } + if (i == count) + pr_info("ftrace section at %px sorted properly\n", start); +} +#else +static void test_is_sorted(unsigned long *start, unsigned long count) +{ +} +#endif + static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end) @@ -6414,6 +6435,8 @@ static int ftrace_process_locs(struct module *mod, if (!IS_ENABLED(CONFIG_BUILDTIME_TABLE_SORT) || mod) { sort(start, count, sizeof(*start), ftrace_cmp_ips, NULL); + } else { + test_is_sorted(start, count); } start_pg = ftrace_allocate_pages(count); |